In present day well logging techniques gamma ray, neutron and epi-thermal neutron logs are used to determine specific parameters such as porosity, shaliness, etc. These types of logs require radioactivity counting which result in an electrical pulse every count.
Often well boreholes are several miles deep. To permit transmission of electrical pulses over this great distance, the signals must be greatly amplified. Even after amplification, the distinctness of the pulses cannot be maintained precisely and several closely spaced pulses may merge. This merging may result in inaccurate radioactivity counts which may lead to wrong conclusions with respect to porosity or shaliness etc. A solution to pulse merging is to count pulses downhole and transmit the pulse count uphole. This system has its advantages in the number of wires needed when several pulse counting types of logging tools (such as thermal neutron, epi thermal neutron and gamma ray) are being used simultaneously.